A previously overlooked, highly diverse early Pleistocene elasmobranch assemblage from southern Taiwan

Abstract

The Niubu fossil locality in Chiayi County, southern Taiwan is best known for its rich early Pleistocene marine fossils that provide insights into the poorly understood past diversity in the area. The elasmobranch teeth at this locality have been collected for decades by the locals, but have not been formally described and have received little attention. Here, we describe three museum collections of elasmobranch teeth (n = 697) from the Liuchungchi Formation (1.90–1.35 Ma) sampled at the Niubu locality, with an aim of constructing a more comprehensive view of the past fish fauna in the subtropical West Pacific. The assemblage is composed of 20 taxa belonging to nine families and is dominated by Carcharhinus and Carcharodon. The occurrence of †Hemipristis serra is of particular importance because it is the first Pleistocene record in the area. We highlight high numbers of large Carcharodon carcharias teeth in our sample correlating to body lengths exceeding 4 m, along with the diverse fossil elasmobranchs, suggesting that a once rich and thriving marine ecosystem in an inshore to offshore shallow-water environment during the early Pleistocene in Taiwan.

The Elasmobranch Fossil Record of the Indo-Australian Archipelago since the Miocene: A Literature Review and New Discoveries from Northern Borneo

“…Data from recently 1 and 2). Data from recently published revised Pleistocene elasmobranch fauna from Taiwan, situated just north of South China Sea and the IAA, are also included [71]. Note that sporadic occurrences are not illustrated here (Sumatra, Timor, see Table 2 The second contrast between the regional fauna is the presence of more open-water taxa, especially within the Lamniformes.…”

“…This approach was applied to Pleistocene elasmobranch fauna from the subtropical region of Taiwan, an island north of the IAA, at the northern rim of the South China Sea. Museum collections were adequately revised, new field data were obtained, which revealed remarkable palaeobiodiversity with better evaluated palaeoecological conditions [71] (Figure 9).…”

“…Comparative chart of the presence of different elasmobranch taxa in the Indo-Australian Archipelago during the Miocene and the Pleistocene (see also Tables1 and 2). Data from recently published revised Pleistocene elasmobranch fauna from Taiwan, situated just north of South China Sea and the IAA, are also included[71]. Note that sporadic occurrences are not illustrated here (Sumatra, Timor, see Table2).…”

New Acropomatiform Fossils From the Upper Kueichulin Formation (Lower Pliocene), Northern Taiwan

“…In contrast to the extensive diversity observed in the contemporary fish fauna, the records of fish fossils in the tropical-subtropical West Pacific region are notably limited and elusive. Despite ongoing efforts and the accumulation of knowledge related to some taxa, such as elasmobranchs (e.g., Marramà et al 2018;Kocsis et al 2019;Lin et al 2022b), the overall understanding of palaeoichthyology in this region remains conspicuously sparse. As a result, significant portions of this vast expanse continue to be terra incognita in the field of palaeoichthyology.…”